Intramolecular hydroamination of alkynes driven by isomeric Au₃₆(SR)₂₄ nanocluster catalysts

It remains elusive to realize the distinct catalysis of isomeric catalysts because it becomes challenging to identify structural isomers in the polydisperse nanoparticles. Herein we investigate catalysis of two geometric isomers for 36-gold-atom nanoclusters with different Au cores arrangements but the same thiolate ligands, thereby providing access to isomer catalysts readily participate in a desired reaction. Compared to the Au₃₆(SR)₂₄ with a one-dimensional (1D) layout of Au₄ tetrahedral units, the Au₃₆(SR)₂₄ with a two-dimensional (2D) layout of Au₄ tetrahedral units is more effective for the intramolecular hydroamination of alkyne. Our study suggests that the exposed Au sties of the two Au₃₆(SR)₂₄ catalysts favor different reaction intermediates and pathways. The intramolecular H transfer leads to intermediates with the C–N and with C=N for the 1D and 2D Au₃₆(SR)₂₄ respectively, and hence the different on-site and off-site pathways for the successive reaction steps account for the different performances of the two Au₃₆(SR)₂₄ catalysts.